Peripheral Bronchoscopy Research Articles

The Importance of Digital Lung Tomosynthesis in Overcoming Computed-Tomography-to-Body Divergence During Bronchoscopic Biopsies of Peripheral Lung Nodules.

The advent of robotic bronchoscopy coupled with electromagnetic navigation bronchoscopy (EMN) and shape-sensing technology have increased diagnostic yields for peripheral pulmonary nodules compared to traditional bronchoscopy. Yet, diagnostic yields from these bronchoscopic platforms still fall short of where they should be. This shortfall is in large part due to a lack of advanced imaging during peripheral bronchoscopy and computed tomography (CT)-to-body divergence (CTBD). Digital lung tomosynthesis (DLT) is an advanced imaging modality that helps overcome CTBD during bronchoscopic biopsies of lung nodules. DLT is a quasi-3D imaging technique, which reconstructs tomographic images of the lung from a series of 2D fluoroscopic projection images. These images can be acquired either using a digital flat panel fluoroscopy machine or a fluoroscopy machine with a more traditional image-intensifier present in most standard bronchoscopy suites. This review aims to explain the mechanisms of both CTBD and DLT to help diagnose early-stage lung cancer more effectively.

Ultrathin Bronchoscopy Without Virtual Navigation for Diagnosis of Peripheral Lung Lesions

BackgroundThe increasing incidence of encountering lung nodules necessitates an ongoing search for improved diagnostic procedures. Various bronchoscopic technologies have been introduced or are in development, but further studies are needed to define a method that fits best in clinical practice and health care systems.Research questionHow do basic bronchoscopic tools including a combination of thin (outer diameter 4.2 mm) and ultrathin bronchoscopes (outer diameter 3.0 mm), radial endobronchial ultrasound (rEBUS) and fluoroscopy perform in peripheral pulmonary lesion diagnosis?Study Design and MethodsThis is a retrospective review of the performance of peripheral bronchoscopy using thin and ultrathin bronchoscopy with rEBUS and 2D fluoroscopy without a navigational system for evaluating peripheral lung lesions in a single academic medical center from 11/2015 to 1/2021. We used a strict definition for diagnostic yield and assessed the impact of different variables on diagnostic yield, specifically after employment of the ultrathin bronchoscope. Logistic regression models were employed to assess the independent associations of the most impactful variables.ResultsA total of 322 patients were included in this study. The median of the long axis diameter was 2.2 cm and the median distance of the center of the lesion from the visceral pleural surface was 1.9 cm. Overall diagnostic yield was 81.3% after employment of the ultrathin bronchoscope, with more detection of concentric rEBUS views (93% vs. 78%, p < 0.001). Sensitivity for detecting malignancy also increased from 60.5% to 74.7% (p = 0.033) after incorporating the ultrathin scope into practice, while bronchus sign and peripheral location of the lesion were not found to affect diagnostic yield. Concentric rEBUS view, solid appearance, upper/middle lobe location and larger size of the nodules were found to be independent predictors of successful achievement of diagnosis at bronchoscopy.Interpretation: This study demonstrates a high diagnostic yield of biopsy of lung lesions achieved by utilization of thin and ultrathin bronchoscopes. Direct visualization of small peripheral airways with simultaneous rEBUS confirmation increased localization rate of small lesions in a conventional bronchoscopy setting without virtual navigational planning.

Robotic-Assisted Bronchoscopy: A Comprehensive Review of System Functions and Analysis of Outcome Data.

The past two decades have witnessed a revolutionary era for peripheral bronchoscopy. Though the initial description of radial endobronchial ultrasound can be traced back to 1992, it was not until the mid-2000s that its utilization became commonplace, primarily due to the introduction of electromagnetic navigation (EMN) bronchoscopy. While the diagnostic yield of EMN-assisted sampling has shown substantial improvement over historical fluoroscopy-assisted bronchoscopic biopsy, its diagnostic yield plateaued at around 70%. Factors contributing to this relatively low diagnostic yield include discrepancies in computed tomography to body divergence, which led to unsuccessful lesion localization and resultant unsuccessful sampling of the lesion. Furthermore, much of peripheral bronchoscopy utilized a plastic extended working channel whose tips were difficult to finely aim at potential targets. However, the recent introduction of robotic-assisted bronchoscopy, and its associated stability within the peripheral lung, has ignited optimism for its potential to significantly enhance the diagnostic performance for peripheral lesions. Moreover, some envision this technology eventually playing a pivotal role in the therapeutic delivery to lung tumors. This review aims to describe the currently available robotic-assisted bronchoscopy technologies and to discuss the existing scientific evidence supporting these.

Preventing atelectasis during bronchoscopy under general anesthesia.

Atelectasis is a well-defined phenomenon in patients having surgery under general anesthesia. Recently, this phenomenon was also reported in patients having bronchoscopy under general anesthesia, with dedicated studies demonstrating a high incidence of up to 89%. Not surprisingly, time under general anesthesia and a higher body mass index (BMI) were found to be two significant factors that influenced the development of intraprocedural atelectasis. Atelectasis poses a significant obstacle in peripheral bronchoscopy since it can result in false positive radial probe ultrasound images, create computed tomography to body divergence, as well as obscure the target lesion on intraprocedural cone beam computed tomography (CBCT) images, thereby affecting both the navigational and diagnostic yield of the procedure. Bronchoscopists should be aware of this phenomenon and make efforts to prevent it when peripheral bronchoscopy under general anesthesia is planned. Ventilatory strategies to reduce intraprocedural atelectasis have been studied and proven to be effective and well-tolerated. Other strategies, such as patient positioning and preprocedural strategies have also been described but need further investigation. This article aims to summarize the recent history regarding the discovery and significance of intraprocedural atelectasis during bronchoscopy under general anesthesia and the various state-of-the-art strategies that have been proposed to mitigate the development of this entity.

Bronchoscopic Evaluation of a Steerable Needle for Simulated Tumor Targets in the Lung Periphery: A Feasibility Study (Bullseye)

Background: Peripheral bronchoscopy is often performed to biopsy peripheral pulmonary lesions. Despite technological advancements to improve reach and access to the lung periphery, the diagnostic yield of peripheral bronchoscopy has been inconsistent, and challenging, particularly for lesions that are adjacent to peripheral bronchi. Current biopsy instruments are reliant on the catheter or scope to align properly with targeted lesions. Objectives: This study evaluates the feasibility of using a steerable biopsy needle to gain access to peripheral tumor targets in a cadaveric model. Methods: Simulated tumor targets 10–30 mm in axial diameter were placed into human cadavers. Bronchoscopy was performed using a 4.2 mm OD flexible bronchoscope, CT-anatomic correlation, and multi-planar fluoroscopy for lesion localization. Once at the targeted location, a steerable needle was deployed and the needle position was determined to be in the central zone, peripheral zone, or outside of the lesion by cone beam CT imaging. If the needle position was within the lesion, a fiducial marker was deployed to mark the needle position, and the needle was articulated and/or rotated in an attempt to place another fiducial marker into a different location within the same lesion. If the needle was outside of the lesion, the bronchoscopist was provided with two additional attempts to gain access to the lesion. Results: Fifteen tumor targets were placed with a mean lesion size of 20.4 mm. The majority of lesions were located in the upper lobes. One fiducial marker was placed in 93.3% of lesions and a second fiducial marker was successfully placed in 80% of lesions. A fiducial marker was placed within the central zone in 60% of lesions. Conclusion: The steerable needle was successfully placed within 93% of targeted lesions 10–30 mm in diameter in a cadaveric model, with the ability steer the instrument into another portion of the lesion in 80% of cases. The ability to steer and control needle positioning toward and within peripheral lesions may complement existing catheter and scope technology during peripheral diagnostic procedures.

Mobile Cone-Beam CT-Assisted Bronchoscopy for Peripheral Lung Lesions

Peripheral bronchoscopy with the use of thin/ultrathin bronchoscopes and radial-probe endobronchial ultrasound (RP-EBUS) has been associated with a fair diagnostic yield. Mobile cone-beam CT (m-CBCT) could potentially improve the performance of these readily available technologies. We retrospectively reviewed the records of patients undergoing bronchoscopy for peripheral lung lesions with thin/ultrathin scope, RP-EBUS, and m-CBCT guidance. We studied the performance (diagnostic yield and sensitivity for malignancy) and safety (complications, radiation exposure) of this combined approach. A total of 51 patients were studied. The mean target size was 2.6 cm (SD, 1.3 cm) and the mean distance to the pleura was 1.5 cm (SD, 1.4 cm). The diagnostic yield was 78.4% (95 CI, 67.1-89.7%), and the sensitivity for malignancy was 77.4% (95 CI, 62.7-92.1%). The only complication was one pneumothorax. The median fluoroscopy time was 11.2 min (range, 2.9-42.1) and the median number of CT spins was 1 (range, 1-5). The mean Dose Area Product from the total exposure was 41.92 Gy·cm2 (SD, 11.35 Gy·cm2). Mobile CBCT guidance may increase the performance of thin/ultrathin bronchoscopy for peripheral lung lesions in a safe manner. Further prospective studies are needed to corroborate these findings.

State of the art: peripheral diagnostic bronchoscopy.

Lung cancer is the leading cause of cancer related death worldwide and in the United States according to the World Health Organization and National Cancer Institute. Improvements in the diagnosis and treatment of lung cancer are of the utmost importance. A prompt diagnosis is a crucial factor to improve outcomes in the treatment of lung cancer. Although the implementation of lung cancer screening guidelines and the overall steady growth in the use of computed tomography have improved the likelihood of detecting lung cancer at an earlier stage, the diagnosis of peripheral pulmonary lesions (PPLs) has remained a challenge. The bronchoscopic techniques for PPL sampling have historically offered modest diagnostic yields at best in comparison to computed tomography guided transthoracic needle aspiration (TTNA). Fortunately, recent advances in technology have ushered in a new era of diagnostic peripheral bronchoscopy. In this review, we discuss the introduction of advanced intraprocedural imaging included digital tomosynthesis (DT), augmented fluoroscopy (AF), and cone beam computed tomography. We discuss robotic assisted bronchoscopy with a review of the currently available platforms, and we discuss the implementation of novel biopsy tools. These technologic advances in the bronchoscopic approach to PPLs offer greater diagnostic certainty and pave the way toward peripheral therapeutics in bronchoscopy.

ASSESSING THE DIAGNOSTIC YIELD AND SAFETY PROFILE OF A NEW ROBOTIC-ASSISTED BRONCHOSCOPY PROGRAM IN A HIGH-RISK PATIENT POPULATION

ASSESSING THE DIAGNOSTIC YIELD AND SAFETY PROFILE OF A NEW ROBOTIC-ASSISTED BRONCHOSCOPY PROGRAM IN A HIGH-RISK PATIENT POPULATION

Rapid On-site Evaluation Practice Variability Appraisal (ROSE PETAL) survey.

Rapid on-site evaluation (ROSE) is frequently used during diagnostic procedures in patients with or suspected to have lung cancer. There is variation in ROSE use among bronchoscopists, and discussion of ROSE results can have significant consequences for patients. This study was performed to define ROSE practice and result disclosure patterns among bronchoscopists. This cross-sectional study was performed using an electronic survey disseminated to the members of the American Association for Bronchology and Interventional Pulmonology and the Society for Advanced Bronchoscopy. The questions centered around ROSE availability, utilization, barriers, and discussion of results with patients. There were 137 respondents. Most identified themselves as interventional pulmonologists (109, 80%); most respondents worked in an academic setting (71, 52%). Availability of ROSE was reported by 121 (88%) respondents. Time constraints (28%), availability of cytology (22%), and scheduling conflicts (20%) were the most reported barriers to ROSE use. Endobronchial ultrasound transbronchial needle aspiration (85%) and nonrobotic peripheral bronchoscopy (65%) were the most reported procedures that used ROSE. There was heterogeneity regarding discussion of ROSE results with the patient or their caregiver in the immediate postprocedure setting: yes - always (40, 33%), yes - sometimes (32, 26%), yes - rarely (18, 15%), or no (31, 26%). Thirty-eight respondents reported they believed ROSE was ≥90% concordant with final cytology results. The results confirmed the heterogeneity of practice patterns. Estimates of ROSE-final cytology concordance were lower than previously published concordance results. Notably, the discussion of ROSE results varied significantly.

Ventilatory Strategy to Prevent Atelectasis During Bronchoscopy Under General Anesthesia: A Multicenter Randomized Controlled Trial (Ventilatory Strategy to Prevent Atelectasis -VESPA- Trial)

Atelectasis negatively influences peripheral bronchoscopy, increasing CT scan-body divergence, obscuring targets, and creating false-positive radial-probe endobronchial ultrasound (RP-EBUS) images. Can a ventilatory strategy reduce the incidence of atelectasis during bronchoscopy under general anesthesia? Randomized controlled study (1:1) in which patients undergoing bronchoscopy were randomized to receive standard ventilation (laryngeal mask airway, 100%Fio2, zero positive end-expiratory pressure [PEEP]) vsa ventilatory strategy to prevent atelectasis (VESPA) with endotracheal intubation followed by a recruitment maneuver, Fio2 titration (< 100%), and PEEP of 8 to 10cm H2O. All patients underwent chest CT imaging and a survey for atelectasis with RP-EBUS bilaterally on bronchial segments 6, 9, and 10 after artificial airway insertion (time 1) and 20 to 30min later (time 2). Chest CT scans were reviewed by a blinded chest radiologist. RP-EBUS images were assessed by three independent, blinded readers. The primary end point was the proportion of patients with any atelectasis (either unilateral or bilateral) at time 2 according to chest CT scan findings. Seventy-six patients were analyzed, 38 in each group. The proportion of patients with any atelectasis according to chest CT scan at time 2 was 84.2%(95%CI, 72.6%-95.8%) in the control group and 28.9%(95%CI, 15.4%-45.9%) in the VESPA group (P< .0001). The proportion of patients with bilateral atelectasis at time 2 was 71.1%(95%CI, 56.6%-85.5%) in the control group and 7.9%(95%CI, 1.7%-21.4%) in the VESPA group (P< .0001). At time 2, 3.84 ± 1.67 (mean ± SD) bronchial segments in the control group vs1.21 ± 1.63 in the VESPA group were deemed atelectatic (P< .0001). No differences were found in the rate of complications. VESPA significantly reduced the incidence of atelectasis, was well tolerated, and showed a sustained effect over time despite bronchoscopic nodal staging maneuvers. VESPA should be considered for bronchoscopy when atelectasis is to be avoided. ClinicalTrials.gov; No.: NCT04311723; URL: www. gov.

The Impact of Alternative Approaches to Diagnostic Yield Calculation in Studies of Bronchoscopy

In recent years, there have been notable advancements in the guidance technologies for peripheral bronchoscopy, including newer electromagnetic navigation platforms, cone beam CT, augmented fluoroscopy, digital tomosynthesis, and robot-assisted bronchoscopy.1-7 As a result, multiple recent trials evaluating the performance of these technologies have been reported. The most frequently employed assessment metric is diagnostic accuracy, frequently termed diagnostic yield (DY) in the bronchoscopy literature, yet there remains no standardized approach to measurement of this outcome in studies of bronchoscopy.

Feasibility of Ultra-Low-Dose CT for Bronchoscopy of Peripheral Lung Lesions.

Background and objectives: Thin-section computed tomography (CT) is essential for identifying small bronchi during bronchoscopy using radial endobronchial ultrasound. Some patients should receive an additional CT for a thin-section image. We performed a retrospective study with a prospectively collected database to identify the optimal radiation dose for thin-section CT during peripheral bronchoscopy. Materials and Methods: In total, 91 patients with peripheral lung lesions underwent thin-section CT (both standard CT as a reference and ultra-low-dose CT (ultra-LDCT)). The patients were randomly assigned to one of four groups according to the ultra-LDCT parameters: group 1 = 120 kVp, 25 mAs; group 2 = 100 kVp, 15 mAs; group 3 = 120 kVp, 5 mAs; and group 4 = 100 kVp, 5 mAs. Two radiologists and two physicians analyzed both the standard CT and ultra-LDCT. Results: The effective doses (EDs) of ultra-LDCT significantly differed among the four groups (median EDs were 0.88, 0.34, 0.19, and 0.12 mSv for groups 1–4, respectively; p < 0.001). Median differences in peripheral airway wall thickness were higher in group 4 than in other groups (differences in median wall thickness measured by two radiologists were 0.4–0.5 mm and 0.8–0.9 mm for groups 1–3 and group 4, respectively). Bronchus signs on ultra-LDCT in groups 1 and 2 were well correlated with those of the standard-dose CT (accuracies of two radiologists and two pulmonary physicians were 95–100%). Conclusions: Our results indicate that ultra-LDCT with ED of >0.34 mSv (ED of group 2) is feasible for peripheral bronchoscopy.

Incidence and Location of Atelectasis Developed During Bronchoscopy Under General Anesthesia: The I-LOCATE Trial

Despite the many advances in peripheral bronchoscopy, its diagnostic yield remains suboptimal. With the use of cone-beam CT imaging we have found atelectasis mimicking lung tumors or obscuring them when using radial-probe endobronchial ultrasound (RP-EBUS), but its incidence remains unknown. What are the incidence, anatomic location, and risk factors for developing atelectasis during bronchoscopy under general anesthesia? We performed a prospective observational study in which patients undergoing peripheral bronchoscopy under general anesthesia were subject to an atelectasis survey carried out by RP-EBUS under fluoroscopic guidance. The following dependent segments were evaluated: right bronchus 2 (RB2), RB6, RB9, and RB10; and left bronchus 2 (LB2), LB6, LB9, and LB10. Images were categorized either as aerated lung ("snowstorm" pattern) or as having a nonaerated/atelectatic pattern. Categorization was performed by three independent readers. Fifty-seven patients were enrolled. The overall intraclass correlation agreement among readers was 0.82 (95%CI, 0.71-0.89). Median time from anesthesia induction to atelectasis survey was 33min (range, 3-94 min). Fifty-one patients (89%; 95%CI, 78%-96%) had atelectasis in at least one of the eight evaluated segments, 45 patients (79%) had atelectasis in at least three, 41 patients (72%) had atelectasis in at least four, 33 patients (58%) had atelectasis in at least five, and 18 patients (32%) had atelectasis in at least six segments. Right and left B6, B9, and B10 segments showed atelectasis in > 50%of patients. BMI and time to atelectasis survey were associated with increased odds of having more atelectatic segments (BMI: OR, 1.13 per unit change; 95%CI, 1.034-1.235; P= .007; time to survey: OR, 1.064 per minute; 95%CI, 1.025-1.105; P= .001). The incidence of atelectasis developing during bronchoscopy under general anesthesia in dependent lung zones is high, and the number of atelectatic segments is greater with higher BMI and with longer time under anesthesia. ClinicalTrials.gov; No.: NCT03523689; URL: www.clinicaltrials.gov.

Urgent bronchoscopy for foreign body aspiration: 48 children among 1096 patients

Objective: Foreign body aspiration (FBA) is a potentially life-threatening emergency in children. Urgent rigid bronchoscopy (URB) should be performed when presentation includes severe respiratory failure with suspicion for FBA. To the best of the knowledge, this is the first study that evaluates URB in English literature.&#x0D; Methods: Forty-eight patients who underwent URB were included in this study. From the medical records, the patients’ demographic characters, endotracheal intubation status, peripheral oxygen saturation, bronchoscopy results, type and location of foreign body (FB), intra- and postoperative complications and mortality, X-ray, length of hospital stay were evaluated.&#x0D; Results: Twenty-four of the 48 patients were non-intubated. Peripheral oxygen saturation values were 60 ± 14.40 in the preoperative period. No statistical differences were found between intubated and non-intubated patients in terms of intra- and postoperative complications. There were no statistical differences between patients with negative and positive results for bronchoscopy in terms of intra- and postoperative complications.&#x0D; Conclusions: Bronchoscopy is not without risk; however, it is a life-saving procedure. Despite negative FB results, urgent bronchoscopy should be performed in suspicious cases.

Bronchoscopic Laser Interstitial Thermal Therapy: An Experimental Study in Normal Porcine Lung Parenchyma.

Population aging and lung cancer screening strategies may lead to an increase in detection of early-stage lung cancer in medical inoperable patients. Recent advances in peripheral bronchoscopy have made it a suitable platform for ablation of small peripheral tumors. We investigated the tissue-ablative effect of a diode laser bronchoscopically applied by a laser delivery fiber (LDF) with wide aperture on porcine lung parenchyma. Laser was tested ex vivo and in vivo to identify the most effective power settings and LDF. Chest computed tomography (CT) were obtained immediately after ablation and after 3 days of observation. At day 3, necropsy was performed. On the basis of our ex vivo and in vivo experiments, we selected the round-tip LDF to be activated at 25 W for 20 seconds. Ten ablations were performed in 5 pigs. One ablation resulted in a pneumothorax requiring aspiration. All animals remained stable for 72 hours. CT findings at days 1 and 3 showed an area of cavitation surrounded by consolidation and ground glass. Median size of CT findings (long axis) was 26 mm (range, 24 to 38) at day 1, and 34 mm (range, 30 to 44) at day 3. Necropsy showed an area of central char measuring from 0.8×0.7×0.9 cm to 2.4×3.5×1.2 cm, surrounded by a gray-brown to dark red area. On histology, variable degrees of necrosis were evident around the charred areas. Bronchoscopic laser interstitial thermal therapy can achieve relatively large areas of ablation of normal lung parenchyma with a low rate of periprocedural complications.

Determining the shift of a bronchoscope catheter from the analysis of a video sequence of a bronchoscope video camera

In this study we have proposed an algorithm for automated monitoring of the movements of a catheter used in peripheral bronchoscopy examination. We have shown that the shift of the catheter can be controlled in an automated way with quite a good accuracy by the means of analysis of video sequence recorded by a video camera of a bronchoscope. For a catheter moving between successive frames by no more than 1/3 of the distance between successive markers associated with a catheter the accuracy of a catheter shift measurement was equal to 1% and for a catheter moving between successive frames by no more than 1/2 of the distance between successive markers associated with a catheter the accuracy of a catheter shift measurement was equal to 5%. Visual inspection proved that the observed measurement errors were associated with faster movements of a catheter. Bronchoscope redesign option is proposed to improve catheter shift measurement accuracy. The results of this study demonstrate that application of image analysis techniques to data recorded during bronchoscopy examination can at least support the existing navigation methods for peripheral bronchoscopy with respect to the determination of the location of the catheter distal tip within the lumen of the pulmonary airways.

Localization of Peripheral Pulmonary Lesions Using a Method of Computed Tomography–Anatomic Correlation and Radial Probe Endobronchial Ultrasound Confirmation

Peripheral pulmonary lesions requiring a diagnosis continue to present challenges to clinicians. One significant barrier is the inability to reliably locate peripheral lesions by bronchoscopic approaches. Multiplanar computed tomographic (CT) scan reconstruction is available to most physicians and provides axial, coronal, and sagittal images that may be used to estimate target lesion location and guide bronchoscopists during procedures. This study was performed to evaluate a systematic method of CT-anatomic correlation based on multiplanar reconstruction CT scanning with monoplanar fluoroscopy during bronchoscopy to locate peripheral pulmonary lesions and confirm lesion location, using radial probe endobronchial ultrasound. A retrospective review of peripheral bronchoscopy cases in which radial probe endobronchial ultrasound for peripheral lesions was performed at a tertiary care, university hospital. All cases involved a systematic approach of reviewing axial, coronal, and sagittal CT reconstructions, coupled with monoplanar fluoroscopy during procedures to assist with locating peripheral lesions. Using the method of CT-anatomic correlation, 332 of 348 (95.4%) of all lesions were successfully localized and confirmed, using radial probe endobronchial ultrasound. Lesions 1-2 cm in size accounted for 45% of all lesions, and the ability to locate lesions was not significantly different based on lesion size. Mean time to lesion localization was 6.8 minutes. Larger lesions and lesions demonstrating an air bronchus sign on CT scan were located in less time. The overall diagnostic yield was 58.9%. A systematic approach applying CT-anatomic correlation with multiplanar CT scan reconstruction and monoplanar fluoroscopy during procedures can result in an efficient, and successful process for locating peripheral pulmonary lesions.

Peripheral Bronchoscopy Training Using a Human Cadaveric Model and Simulated Tumor Targets.

Peripheral pulmonary lesions are an increasingly common finding in clinical practice. Electromagnetic navigation and radial probe endobronchial ultrasound have improved the diagnostic yield of bronchoscopy for peripheral lesions, although these techniques remain largely underutilized. One potential barrier to the adoption of these techniques may be the lack of an appropriate model to train clinicians on the various aspects of peripheral bronchoscopy. This report describes the development of a human cadaveric model with artificially implanted tumor targets designed to train physicians on aspects of peripheral bronchoscopy, including electromagnetic navigation and radial probe endobronchial ultrasound.

The Effect of Respiratory Motion on Pulmonary Nodule Location During Electromagnetic Navigation Bronchoscopy

Electromagnetic navigation has improved the diagnostic yield of peripheral bronchoscopy for pulmonary nodules. For these procedures, a thin-slice chest CT scan is performed prior to bronchoscopy at full inspiration and is used to create virtual airway reconstructions that are used as a map during bronchoscopy. Movement of the lung occurs with respiratory variation during bronchoscopy, and the location of pulmonary nodules during procedures may differ significantly from their location on the initial planning full-inspiratory chest CT scan. This study was performed to quantify pulmonary nodule movement from full inspiration to end-exhalation during tidal volume breathing in patients undergoing electromagnetic navigation procedures. A retrospective review of electromagnetic navigation procedures was performed for which two preprocedure CT scans were performed prior to bronchoscopy. One CT scan was performed at full inspiration, and a second CT scan was performed at end-exhalation during tidal volume breathing. Pulmonary lesions were identified on both CT scans, and distances between positions were recorded. Eighty-five pulmonary lesions were identified in 46 patients. Average motion of all pulmonary lesions was 17.6 mm. Pulmonary lesions located in the lower lobes moved significantly more than upper lobe nodules. Size and distance from the pleura did not significantly impact movement. Significant movement of pulmonary lesions occurs between full inspiration and end-exhalation during tidal volume breathing. This movement from full inspiration on planning chest CT scan to tidal volume breathing during bronchoscopy may significantly affect the diagnostic yield of electromagnetic navigation bronchoscopy procedures.

Radial Probe Endobronchial Ultrasound for Peripheral Pulmonary Lesions. A 5-Year Institutional Experience

Technological advances have improved the ability of bronchoscopists to access peripheral pulmonary lesions for tissue sampling. Radial probe endobronchial ultrasound (EBUS) provides real-time feedback to guide biopsies of peripheral lesions, thereby potentially improving diagnostic yield over conventional bronchoscopy. We assessed the overall diagnostic yield of peripheral bronchoscopy using radial probe EBUS for peripheral pulmonary lesions, as well as factors that might influence the diagnostic yield, such as radial ultrasound view, lesion size, and ability to locate the peripheral lesion. We conducted a retrospective review of peripheral bronchoscopy cases in which radial probe EBUS was utilized to diagnose peripheral pulmonary lesions at a tertiary care university hospital. Our study cohort comprised 496 patients who underwent bronchoscopies between January 2008 and December 2012 for the diagnosis of peripheral pulmonary lesions. Radial probe EBUS was used alone for diagnostic purposes in 467 patients. A diagnosis was made on that basis in 321 (69%) of 467 patients. A diagnosis was obtained for 83 of 144 (58%) of nodules 1-2 cm in diameter, 99 of 137 (72%) of nodules 2.1-3 cm, 54 of 70 (77%) of nodules 3.1-4 cm, 41 of 47 (87%) of nodules 4.1-5 cm, and 35 of 40 (88%) of nodules larger than 5.1 cm. Of all 467 nodules, 446 (96%) were successfully identified using radial probe EBUS. When the radial probe position was within the target lesion, the diagnostic yield was 84% compared with 48% when the probe was positioned adjacent to the lesion. Radial probe EBUS can be used to guide biopsy during peripheral bronchoscopy. This technique provides real-time ultrasound-based confirmation of target lesion localization prior to biopsy. Using radial probe EBUS, the vast majority of peripheral pulmonary nodules can be identified. Radial EBUS probe position relative to the target lesion significantly affects the diagnostic yield.